The present description relates a lithography system configured to apply a pattern to a substrate, the system comprising, e.g.: a track unit configured to apply a layer on the substrate for lithographic exposure, a lithography apparatus configured to expose the layer according to the pattern, a metrology unit configured to measure a property of the exposed pattern in the layer, a control unit configured to control an automatic substrate flow among the track unit, the lithography apparatus, and the metrology unit, and a machine learning controller configured to control the system to optimize the property of the pattern.
An example of such a lithography system is known from U.S. Pat. No. 6,979,522. In the system of U.S. Pat. No. 6,979,522, a lot (also called a “batch”) of substrates is exposed after alignment in a lithography apparatus wherein alignment parameters are determined. Using a formula with tool specific coefficients, the overlay accuracy can be calculated (predicted) from these alignment parameters in advance. Next, the exposure tool-offset can be adjusted on a substrate-to-substrate basis to correct for the derived overlay inaccuracy. Moreover, the alignment parameters for a specific substrate can be used to change the tool-offset for the same substrate prior to exposure.